Parasaurolophus
Parasaurolophus ("near crested lizard"Liddell, Henry George and Robert Scott (1980). A Greek-English Lexicon (Abridged Edition). United Kingdom: Oxford University Press. ISBN 0-19-910207-4.) is a hadrosaurid dinosaur that lived in the Late Cretaceous Period of North America. Description Parasaurolophus is estimated to have grown to a length of 9.5 meters and weighed up to 2.5 tonnes.Glut, Donald F. (1997). "Parasaurolophus". Dinosaurs: The Encyclopedia. Jefferson, North Carolina: McFarland & Co. pp. 678–684. ISBN 0-89950-917-7. Like other hadrosaurs, it could walk on both two and four legs.Horner, John R.; Weishampel, David B.; and Forster, Catherine A (2004). "Hadrosauridae". In Weishampel, David B.; Osmólska, Halszka; and Dodson, Peter (eds.). The Dinosauria (2nd ed.). Berkeley: University of California Press. pp. 438–463. ISBN 0-520-24209-2. Skin impressions are known from P. walkeri, showing round, uniform scales. The most distinctive feature of Parasaurolophus was its cranial crest. This crest was hollow, and differed slightly between species.Norman, David B. (1985). "Hadrosaurids II". The Illustrated Encyclopedia of Dinosaurs: An Original and Compelling Insight into Life in the Dinosaur Kingdom. New York: Crescent Books. pp. 122–127. ISBN 0-517-46890-5. Classification Parasaurolophus is a lambeosaurine hadrosaur, in the same subfamily as Corythosaurus and Lambeosaurus.Weishampel, David B.; and Horner, Jack R. (1990). "Hadrosauridae". In Weishampel, David B.; Osmólska, Halszka; and Dodson, Peter (eds.). The Dinosauria (1st ed.). Berkeley: University of California Press. pp. 534–561. ISBN 0-520-06727-4. Its closest relative is probably Charonosaurus, which has a similar skull.Godefroit, Pascal; Shuqin Zan; and Liyong Jin (2000). "Charonosaurus jiayinensis n. g., n. sp., a lambeosaurine dinosaur from the Late Maastrichtian of northeastern China". Compte Rendus de l'Academie des Sciences, Paris, Sciences de la Terre et des planètes 330 (12): 875–882. doi:10.1016/S1251-8050(00)00214-7. There are three known species, P. walkeri,Parks, William A. (1922). "Parasaurolophus walkeri, a new genus and species of crested trachodont dinosaur". University of Toronto Studies, Geology Series 13: 1–32. P. cyrtocristatus,Ostrom, John H. (1961). "A new species of hadrosaurian dinosaur from the Cretaceous of New Mexico". Journal of Paleontology 35 (3): 575–577. and P. tubicen.Wiman, Carl (1931). "Parasaurolophus tubicen, n. sp. aus der Kreide in New Mexico". Nova Acta Regia Societas Scientarum Upsaliensis, series 4 (in German) 7 (5): 1–11. This is a cladogram used in the 2007 redescription of Lambeosaurus:Evans, David C.; and Reisz, Robert R. (2007). "Anatomy and relationships of Lambeosaurus magnicristatus, a crested hadrosaurid dinosaur (Ornithischia) from the Dinosaur Park Formation, Alberta". Journal of Vertebrate Paleontology 27 (2): 373–393. doi:10.1671/0272-4634(2007)27373:AAROLM2.0.CO;2. Retrieved 2007-07-28. }} }} |label2= |2= |label2= |2= }} }} }} }} }} }} }} }} }} }} History The first specimen of Parasaurolophus was first discovered in what is now the Dinosaur Park Formation along the Red Deer River in Alberta, Canada in 1920. William Parks described the dinosaur as Parasaurolophus walkeri in 1922, in honor of Sir Edmund Byron Walker, who was Chairman of the Board of Trustees of the Royal Ontario Museum at the time. Its name means "near crested lizard" in reference to the observation that it looked superficially similar to Saurolophus ("crested lizard"). Not many specimens of the species have since been found, nor have many examples of the genus been found in Canada.Currie, Phillip J; and Russell, Dale A. "Geographic and stratigraphic distribution of dinosaur remains" in Dinosaur Provincial Park, p. 553. In 1921, paleontologist Charles H. Sternberg discovered a partial skull in the Kirtland Formation of New Mexico. The specimen was sent to Sweden, where Carl Wiman described it as P. tubicen. A second skull of the species was found in 1995 and described in 1999.Sullivan, Robert M.; and Williamson, Thomas E. (1999). A new skull of Parasaurolophus (Dinosauria: Hadrosauridae) from the Kirtland Formation of New Mexico and a revision of the genus. New Mexico Museum of Natural History and Science Bulletin, 15. Albuquerque, New Mexico: New Mexico Museum of Natural History and Science. pp. 1–52. John Ostrom described another New Mexico specimen as P. cyrtocristatus in 1961. This species was the smallest of the genus, and possessed a shorter crest. Paleobiology Diet Parasaurolophus was a herbivore that ground its food in a fashion similar to chewing. It had hundreds of teeth packed into dental batteries, and had a beak at the end of its snout. Parasaurolophus could probably have eaten vegetation as high as 4 meters above the ground. Head crest The crest of Parasaurolophus likely had many different functions. Some of these include sexual selection,Evans, David C. (2006). "Nasal cavity homologies and cranial crest function in lambeosaurine dinosaurs". Paleobiology 32 (1): 109–125. doi:10.1666/04027.1. Retrieved 2007-07-28. thermoregulation,Wheeler, P.E. (1978). "Elaborate CNS cooling structure in large dinosaurs". Nature 275 (5679): 441–443. doi:10.1038/275441a0. PMID 692723. and auditory signaling.Sandia National Laboratories (1997-12-05). "Scientists Use Digital Paleontology to Produce Voice of Parasaurolophus Dinosaur". Retrieved 2007-06-30. References Category:Animals Category:Dinosaurs Category:Herbivores Category:Hadrosaurs Category:Fossil taxa described in 1922